


If It Had To Be Someone

by the_painless_moustache



Category: Teen Wolf (TV)
Genre: Bottom Derek, F/M, Knotting, M/M, Mating Cycles/In Heat, Scott's cool with it, Stiles has a knot, Voyeurism, post 3b, threesome time!
Language: English
Status: Completed
Published: 2014-06-09
Updated: 2014-06-09
Packaged: 2018-02-03 23:12:05
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,433
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1759329
Author URL: https://archiveofourown.org/users/the_painless_moustache/pseuds/the_painless_moustache
Summary: <blockquote class="userstuff">
              <p>Kira goes into heat and Scott's not around. Stiles is the next best choice.<br/>(But Derek might be a little jealous.)</p>
            </blockquote>





	If It Had To Be Someone

**Author's Note:**

> This was a prompt for a girl on tumblr that is LONG over-due! It's 2000 words so I thought it was a little long to post there. Posting here instead. Hope you enjoy, dear!

 “Why can’t you ask Scott?!” Stiles squeaks, struggling to get away from the firm weight on top of him.

 Kira whines in her throat, squeezes his hips with her knees and licks a stripe up his throat. “He’s out of town.” she whimpers, rucking up his t-shirt even has he pulls it back down after her. “And you smell good.”

 “Probably because I smell like Scott. _Scott_ , your loving, caring boyfriend. The love of your life, even. With all that rogue wolfish charm and—” Stiles breaks off in a stuttered moan when she grinds down on him, because Stiles is a loyal son of a bitch, but he’s also seventeen.

 Kira grabs his earlobe between her teeth, scrapes her nails through his hair. “I love Scott,” she allows “But I need you, Stiles. You’ve got a piece of fox in you, and it’s— _ahh_ —oh, god, I need you to knot me, Stiles.”

 Stiles squeaks, struggles against her again because this is _not okay_. This is all sorts of not okay. Scott is going to kill him, for one. With betrayed, heartbroken puppy eyes. Hell, Stiles will probably kill himself first. He’ll just throw himself at Scott’s feet and run himself through with Kira’s sword—because she deserves that for doing this to Scott.

 Her phone rings then, and she whines desperately. Stiles scrambles for it, because he _knows_ that ringtone, and he’s got to try and get Kira off him kind of _right now_. He answers with a rushed “Scott, it’s not my fault!”

 “Fuck, Stiles?” Scott sounds breathless. “Why are you…ugh, is she there?”

 Stiles brain is breaking. “Scott are you… _what the hell is going on?_ ”

 “Kira’s in heat. I can feel it even from Washington.”

 “Stop touching your dick!” Stiles snaps. Kira makes a pitiful noise and grinds down on him. He swats her away “Stop touching my dick!”

 “Stiles, look, it’s…this is weird, but you have to. Okay? It’s okay, we talked about it, about how if it had to be someone it should be you.”

 “ _Maybe you should’ve asked me first!_ ”

 “Stiles…” Scott begs, and Stiles winces, snapping back “ _Stop jacking off_.”

 “Sti—what the _fuck?_ ”

 Stiles groans and just lays back because _of course_ fucking _Derek_ would show up. “Kill me.” he begs Derek. “Just, please.”

 But Derek looks very far from killing Stiles. He looks semi-close to killing Kira, but Kira is doing something with her eyes while she’s pulling up his shirt again, and Derek seems to enjoy that, and _fuck_. Stiles turns into the phone “ _You owe me_.”

 “Can I—”

 “No.” Stiles hangs up and throws the phone across the room, rolling and pinning Kira beneath him. She moans and wraps her legs around his waist, still diligently thrusting. Stiles feels the hopelessness settle in as well as the victory his dick experiences. It’s bittersweet. It’s not like he doesn’t like Kira. She’s beautiful, she is, but she’s _Scott’s_ and Stiles isn’t that guy. But Scott’s okay with it, and obviously Kira’s on board, it’s just…he looks at Derek, probably utterly wrecked already. “She’s in heat.”

 “I know.” Derek says, eyes flicking from Stiles’ eyes to his waist. “It’s why I came over.”

 “I’d let you handle it, but—” Kira keens, arms snapping around him and yanking him to her chest. Stiles tries to ignore her mouth on his neck. “But they said it had to be me.”

 “He trusts you most.” Derek agrees gruffly, and…and _oh_.

 Stiles stares at him, dumbfounded and overall just done with this entire situation, honestly. “Are you hard?”

 Derek blushes, setting his jaw to counteract the moment of weakness. “It’s her heat.”

 “It’s me.” Stiles tells him, and by the way Derek’s teeth grind, he knows he’s right. It wasn’t a _secret_ that they were into each other, really. It was just something they ignored because between all their supernatural enemies, it was just easier to not bother. Though Derek hadn’t hesitated in kissing him the moment he’d been himself again, the moment he’d had the strength to mutter _can’t get rid of me that easily._

 Kira growls and bites him. “Focus, Stiles.” she orders roughly.

 “Can he watch?” Stiles asks her, but he’s looking at Derek. Asking them both.

 Kira’s nails scrape through his hair. “Yes, fine, whatever. Fuck me.”

 The nogitsune took a lot from Stiles. Took his friends and his choices, took a piece of his very soul and tore it open, honestly. Defeating it gave Stiles a lot. Clarity, a sense of self he hadn’t had before, a physical strength given him by having something supernatural embedded in his mind. And, of course, what Kira is currently after: his dick. Or rather, the knot at the end of it that Kira’s dying to have inside her.

 He sits back and strips his shirt and studiously focuses on Kira, on the girl beneath him who is currently pulling at her own clothes. He shifts away from her just enough to get his pants and underwear down around his thighs and then Kira is on him, mouth hot and wet and _fuck_ , okay, Stiles can be okay with this. He can do this. Kira looks up, eyes glowing gold as she sucks at the head of his cock, looking for all the world like there is literally nothing better than Stiles at this moment.

 Stiles runs his fingers through her hair, pulls a little and enjoys the way she moans and pushes herself further forward, tongue doing _something_ to the underside of his cock that is way, way too much. He shudders, pulls her back and kisses her. She hums into it. Stiles gets pushed onto his back and gets a breath in before Kira is kissing him again, hands running through his hair and body moving on his in a way that really, _really_ shouldn’t be allowed. Stiles grabs her hips to still them, but it doesn’t work. Her hands find his cock and he feels the slick slide of a condom and then she shifts upwards and—

 “ _Holy fuck_.” Stiles gasps around her mouth. She grins viciously, eyes still glowing, teeth showing a small point to them. She tight, and _really_ wet, and Stiles has no qualms about growling at her and holding her hips down while he fucks upwards.

 She doesn’t kiss him anymore, but she gives it a valiant effort. She’s just whimpering too much as Stiles bounces her on his cock, and Stiles is too busy watching her fall apart to care. He feels the need creep in, all worries about their friendship and Scott forgotten as he growls and rolls her over, grabbing one leg and spreading it far wider than really was needed.

 Kira _screams_ , nails digging into his back, body shuddering, and Stiles knows she’s coming, but this isn’t what she needs. _He’s_ what she needs, and he fucks her hard through it, the bed rocking. She starts gasping something at him, but _fuck_ , Stiles just doesn’t care anymore. There’s not an ounce of him left that cares, and when he knots her he’s not gentle. He forces his hips down, grinds them against her, enjoys the way she comes around him again, and then he swells and she’s locked there, tears falling as she blinks them away. Stiles comes back to himself, wipes them away with gentle thumbs. “I’m sorry, I didn’t…”

 Kira laughs, shakes her head and pulls him down into a hug that feels surprisingly platonic. “It’s okay, Stiles, I’m not mad.” she tells him. There’s a pause full of words and Stiles is about to ask about them when she whispers “He might be, though.”

 Stiles lifts and turns his head, and Derek’s eyes are blue. He’s got his claws dug into Stiles’ computer chair, cracking the plastic arm rests open. Stiles glances down at his crotch, which is swollen and _god,_ wow, Stiles really wants that. Kira’s tracing patterns on his back reassuringly, maybe following the pattern of moles there because Derek growls. She doesn’t stop, just turns lazily to him. “You can have him next.” she promises. She looks at Stiles. “Have you guys…?”

 Stiles shakes his head. “Not yet.”

 She giggles, wiggles to test out his knot, and says “Well, I’m going to guess you’re about to.”

“How long does this take?” Derek demands.

 “Half an hour, maybe?” she guesses. “That’s what the book said.”

 Stiles collapses on her, exhaustion creeping in. She complains about how heavy he is, but he just snorts and pinches her when she does, so eventually she stops. It’s twenty minutes, and he’s still wide, but she wriggles off and strips the condom, tossing it into his garbage before curling against the wall and looking for all the world like she was going to sleep there. When Stiles says so, she snorts. “He can watch me being fucked, but I can’t watch him? That’s not fair. Besides, I’m way too sore to walk home.”

 “Not to mention your mom.” Stiles adds with a shudder. “Okay, fine, you can stay, but it’s Derek’s call on— _fuck!_ ”

 Derek ignores him, licking the come from his dick like it’s his fucking job. He uses just his tongue, laying broad, wide sweeps up until Stiles’ is satisfactorily clean. Then he swallows him whole and works his head up and down until Stiles yanks on his hair with a pained groan. “Dude, still _very_ sensitive.”

 Derek whines, pitifully, and licks at his thigh. His eyes are blue, bright and glowing, and Kira giggles. “Looks like you put him in heat, too.”

 Derek growls quietly and pulls Stiles’ pants and underwear off him before pressing his tongue against the drop of precome Stiles’ is sporting. Stiles sighs and scratches Derek’s head, dropping his head back. “Derek, I’m serious, I’m freaking sensitive as shit. Even if I’m hard.”

 “He’s mine.” Derek growls, ignoring Stiles in favor of glowering at Kira.

 Kira nods, not looking threatened in the least. “Okay. Thank you for letting me borrow him.”

 “I’m not a toy.” Stiles snaps. Derek rumbles and slithers—yes, _slithers_ —up his body, nipping at his throat. “Derek, tell her.” Stiles orders petulantly.

 Derek huffs a near-laugh into his skin but otherwise ignores him, rubbing stubble burn into Stiles’ neck instead. Stiles looks at Kira with a frown. “Why is he doing this?”

 “Claiming process. Someone got to you first, so now he can’t stop himself from making sure everyone knows who you really belong to.”

 Derek bites hard into Stiles’ neck in what almost seems like an agreement. Stiles rolls his eyes and pushes his hips up. “Gonna let me claim you back?” he wonders.

 Derek doesn’t seem opposed at all to this, pulling back to lick at Stiles’ chest while he reaches for the lube and another condom. Only, Derek takes the condom and throws it across the room, rumbling something about it not mattering anyway. Stiles doesn’t particularly care, because Derek’s rubbing a hand over his own cock watching Stiles warm lubes between his fingers, and then arches so Stiles can reach him easily.

 The first finger is easy, just a press and slide that has Stiles desperately optimistic. Derek rocks back into it with fervor, not making the loud, desperate noises Kira was, but still whimpering softly into his neck. The second finger is a bit of a stretch, but Derek takes it easily enough with a roll of his hips before collapsing onto Stiles’ chest. Stiles shivers, the brief friction and simple warm pressure again him insanely perfect.  Stiles turns and runs his teeth into Derek neck.  Derek presses his hips back, sinking Stiles fingers deeper into. Stiles moves them bit and Derek arches back, claws digging into his sheet. “That good?” Stiles asks.

 Derek groans in response.

 His smile bites into Derek’s skin, but Derek doesn’t seem to care. Stiles works another finger into him, splitting them apart just slightly to feel the pull inside him. Derek growls, pulls off to work lube over Stiles’ dick. Stiles arches, shoves. “No, wait!” he squeaks.

 Derek whines—legitimately _whines_ —and tightens his grip. “ _Stiles_.”

 “Too sensitive. God, fuck, get on your knees.”

 Derek obeys, climbs next to Kira and watches Stiles move up behind him Stiles works the three fingers back into him, kisses a mole on Derek’s lower back when he moans. “So pretty.” Stiles praises. “You’re so good like this, you know.”

 Derek drops his forehead to his arms, changing the angle right enough that Stiles can’t miss his prostate. He rips through Stiles sheets, but makes a glorious noise when he does, so Stiles can’t be too mad. He slips his pinky in and Derek turns to look at him, eyes blue and wrecked. “Stiles…please…”

 “I wish I could make this last.” Stiles sighs, slipping out. Derek shivers, but Stiles’ is quick enough to replace his fingers with his cock, sinking in with one smooth motion. Derek growls, presses back. “Fuck, yes.” Stiles breathes, leaning forward. “God, you feel good.”

 Derek reaches back and pulls on his hair. “Fuck me.” he begs. “Fuck me, knot me. God, fuck, _please_.

 Stiles has no qualms about doing just that. He rocks his hips forward, cherishes the noise Derek makes, then pulls him back so he’s sitting on his lap and _that_ drives Derek crazy. Suddenly, Stiles finds himself with a lapful of Derek and it’s fucking _great_. He bounces a few times, desperately, then bottoms out and just sits. Stiles is too sensitive still, is already swelling inside Derek, so he reaches around and grips his cock, teething at Derek’s shoulder. “Are you close? Oh, god, please tell me your close. Fuck, I want to knot you when you come.”

 Derek rocks back into him. He moans, soft and breathy, apparently feeling the pull of Stiles knot on his rim. “Yeah. Yeah, god.”

 Stiles thrusts up, pulls Derek hard against him with one hand and starts jacking him quickly. Derek pulls hard on his hair and growls, and Stiles bites in retaliation. He doesn’t remember coming, or remember Derek coming, actually, until he realizes Derek’s licking come off his fingers and rocking back into his knot, moaning ridiculously around his hand. “Fuck, we’ve come already, Derek.” Stiles groans. “You can stop.”

 He turns and nuzzles Stiles as best he can. Stiles rolls his eyes. Obviously, heat sex made Derek into some pathetically lovely cat. Stiles maneuvers them to the side, his back to Kira who cuddles against him, as well, and Stiles lets them fall asleep while pondering how absolutely _weird_ his life is.

**Author's Note:**

> Hey. Hey you. Wanna see [my tumblr?](http://itsarugsbust.tumblr.com/)


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